Variant sessions showing up on control pages

We are running a test in which mobile users who view our /about page are either shown the original /about page or are redirected to a redesigned page, /about2. I created segments in Google Analytics in order to dig deeper into the experiment results according to this post: https://support.google.com/analytics/answer/4380401?hl=en.

What I'm seeing in Google Analytics is that some of the variant sessions are showing up as having viewed the control page. None of the control sessions are viewing the variant URL, which makes sense. How are the variant sessions showing up in the results for the URL that should only be displayed to the control group?